Synchronizing rings of a vehicle transmission are formed, as a rule, by a conically designed friction ring with friction surfaces on its inner surface area or its outer surface area. If the friction ring has friction surfaces on both surface areas, it is also designated as an intermediate ring. The friction surfaces of an intermediate ring are frictionally connected, during the synchronizing operation on the outer casing, to a friction surface formed on the outer synchronizing ring. At the same time, a friction surface formed on the inner surface area of the intermediate ring is in frictional contact with a friction surface of an inner synchronizing ring. The outer synchronizing ring is connected positively to the synchronizing body and engages into clearances of the inner synchronizing ring, for example, via driver noses which are formed on its side of smaller diameter and which are directed radially inward. The inner synchronizing ring is therefore likewise connected positively to the synchronizing body via the outer synchronizing ring.
A synchronizing device of this type consists of a large number of individual parts and is therefore complicated to produce. For the mass manufacture, it has proved appropriate to produce synchronizing rings in a non-cutting manner from sheet metal by forming. The rings produced by forming, however, have mostly a friction surface which does not satisfy the accuracies required. As a rule, therefore, a cutting remachining or honing is necessary. If a friction lining is glued to a friction surface/any inaccuracies of the annular body are transferred to the friction surface which, in turn, has to be reworked. The application of a friction lining, for example, by adhesive bonding is therefore complicated and cost-intensive.
To avoid this problem, it is proposed in AT 107 755 to subdivide the friction lining into a plurality of elements and to assemble the friction lining in the size and shape desired in each case from a greater or lesser number of such elements. The friction ring consists of a basic body with holes, the walls of which have a conical configuration. Friction bodies are pushed into the holes. A sheet in the form of an arc of a circle is fastened to the basic body by means of screws, and the friction elements are held positively on the inner side of the sheet. In this friction ring, it is necessary that the friction bodies either are held positively by means of relatively complicated and difficult to mount accessories or else are individually fastened non-positively. Both measures require a considerable outlay in terms of production.
A further generic synchronizing ring is known from DE 37 05 657 A1. A synchronizing ring is presented which has a basic body as a supporting ring and which is provided with a friction lining, the friction lining being assembled from a multiplicity of friction bodies which are distributed over the circumference of the friction surface. The friction elements are pressed positively into open recesses of the supporting ring. This method is suitable particularly for sintered rings, but not for all types of friction linings. If the supporting ring and the friction elements are not remachined, then some friction elements are subjected to very much higher load than others when the synchronizing device is in shift operation, and this may lead to a failure of this synchronizing ring.